A Fuck Buddy is a contact who is not your boyfriend or girlfriend, with which you have a purely sexual relationship on the mutual understanding that you both want sex and nothing else.
In other words, no strings attached sex is what you both want and have agreed that sex will be the limit of your relationship.
This can be an excellent arrangement to have with a friend of the opposite sex (or same sex) allowing you both to enjoy long sex sessions without the baggage of a relationship.
In the current generation it is very common for both males and females to seek out this kind of casual sex relationship to satisfy desires and often to gain experience.
Age does not seem to be a factor as we have fuck buddy members from 18 to well above 60, and in fact, some younger members prefer older and some older prefer younger.